fix(lsp): generate markdown including None (#4719)

Author: benfdking

sqlmesh/lsp/description.py

@@ -10,21 +10,20 @@
 def generate_markdown_description(
     model: t.Union[SqlModel, ExternalModel, PythonModel, SeedModel],
 ) -> t.Optional[str]:
+    description = model.description
     columns = model.columns_to_types
     column_descriptions = model.column_descriptions
 
-    columns_table = (
-        "\n".join(
-            [
-                f"| {column} | {column_type} | {column_descriptions.get(column, '')} |"
-                for column, column_type in columns.items()
-            ]
-        )
-        if columns
-        else ""
-    )
+    if columns is None:
+        return description or None
 
-    table_header = "\n\n| Column | Type | Description |\n|--------|------|-------------|\n"
-    return (
-        f"{model.description}{table_header}{columns_table}" if columns_table else model.description
+    columns_table = "\n".join(
+        [
+            f"| {column} | {column_type} | {column_descriptions.get(column, '')} |"
+            for column, column_type in columns.items()
+        ]
     )
+
+    table_header = "| Column | Type | Description |\n|--------|------|-------------|\n"
+    columns_text = table_header + columns_table
+    return f"{description}\n\n{columns_text}" if description else columns_text

tests/lsp/test_description.py

@@ -0,0 +1,32 @@
+from sqlmesh.core.context import Context
+from sqlmesh.lsp.description import generate_markdown_description
+
+
+def test_model_description() -> None:
+    context = Context(paths=["examples/sushi"])
+
+    model_no_description = context.get_model("sushi.order_items")
+    markdown = generate_markdown_description(model_no_description)
+
+    assert markdown == (
+        "| Column | Type | Description |\n"
+        "|--------|------|-------------|\n"
+        "| id | INT |  |\n"
+        "| order_id | INT |  |\n"
+        "| item_id | INT |  |\n"
+        "| quantity | INT |  |\n"
+        "| event_date | DATE |  |"
+    )
+
+    model_with_description = context.get_model("sushi.customers")
+    markdown = generate_markdown_description(model_with_description)
+
+    assert markdown == (
+        "Sushi customer data\n"
+        "\n"
+        "| Column | Type | Description |\n"
+        "|--------|------|-------------|\n"
+        "| customer_id | INT | customer_id uniquely identifies customers |\n"
+        "| status | TEXT |  |\n"
+        "| zip | TEXT |  |"
+    )